I am using the 7 segment display i got from sparkfun to create an alarm clock. It works very well, however I have an issue with the first digit. When I want it to be blank (between 1 and 9 o'clock) i send it 0x78 and it causes the first digit to blink. If i send 0x78 to any of the other digits it clears them just fine. This is only an issue on the first digit. I have also tried using (0x7b)(0x00) and get the problem where it writes so that the numbers all shift one to the left because it is hoping to receive each of the 4 digits in order.

I realized i didn't explain the blink very well. By blink i mean that it cycles between being blank and showing 0. After it rolls over to 1 it continues to blink between 1 and blank.

// Send alphanumeric data to the Sparkfun Serial LED Display (COM-09230) using SPI// Tested using Arduino Pro Mini w/ ATMega168 @ 5V// July 21, 2009 - Quazar & Busaboi// No guarantees expressed or implied just a good starting point// Based upon the many SPI tutorials on Arduino.cc//// "num" specifies the number to display// "base" specifies the base to use (2-16).// Use 2 for binary, 8 for octal, 10 for decimal, or 16 for hex// "pad" indicates whether leading zeros should be replaced with spaces.// pad==0 means spaces (" 0"), pad==1 means zeros ("0000")//// Notes: The display's decimal/punctuation indicators are not changed.// Numbers that don't fit into 4 digits show as " OF " for "Overflow".// Assumptions: "unsigned short" is assumed to be at least 16b wide.#include <Time.h> #include <Wire.h> #include <DS1307RTC.h> // a basic DS1307 library that returns time as a time_t